The present invention is concerned with improvements in and relating to air cargo containers of the type used for the transport of cargo, baggage and mail.
Conventional air cargo containers presently in use are made with a base and an internal framework of columns and beams fixed to the base and defining the aft, forward and lateral side walls, door openings and roof. The framework is spanned by aluminium sheet material riveted to the columns and beams. Surrounding the lower edge of the base there is an outwardly projecting flange which is engaged by clamps fixed to the floor of the aircraft to anchor the container in place. To increase the useful space within the container, the columns of the framework can be stepped laterally outwardly from the plane of their attachment to the base of the container, so that they extend over the flange. This, however, has the disadvantage of weakening the framework in the region of its connection to the base and of making the connection more complex and therefore costly. Furthermore, in use, the walls of adjacent containers have a tendency to bind.
Such air cargo containers are required to conform to various national and international standards and specifications such as those of the U.S. Federal Aviation Administration (FAA), International Air Transport Association (IATA), U.S. National Aerospace Standard Board (NAS), U.S. Federal Aviation Regulations (FAR) and European Joint Aviation Regulations (JAR), which set out the characteristics which such air cargo containers must have, such as, for example, the ability to sustain defined vertical and lateral loads and impacts, shear forces and fire resistance.
Modifications of the conventional air cargo containers as described above, have been proposed, such for example as in Canadian Patent Specification No. 751756, UK Patent Specifications Nos. 1065805, 1284917, 1507042 and 2195613 and U.S. Pat. Nos. 3,563,403, 3,692,203 and 3,968,895, but as far as the applicants are aware none of these proposals have resulted in an air cargo container which conforms to the various national and international standards and specifications referred to above.